1. Field of the Invention
The present invention relates to an electric power steering apparatus for assisting a steering operation.
2. Description of the Related Art
In an electric power steering apparatus in which an assist force corresponding to a detected torque is obtained by an electric motor, it is disclosed that the electric motor is coaxially arranged between an input shaft and an output shaft, in Japanese Utility Model Publication (KOUKAI) No. 56-4973.
3. Problems to be Solved by the Invention
In the electric power steering apparatus described above, there are arranged a torque sensor detecting a torque corresponding to a relative rotational angle difference between the input and output shafts, the electric motor and a reduction mechanism, sequently in line in an axial direction of the shaft. However, since it is required to make shaft lengths of the input and output shafts long, such an apparatus has a drawback to be jumboized as a whole. Further, the torque sensor is arranged so as to be projected outwardly of the apparatus, so that water, dust and the like tend to stick to the torque sensor, whereby there is a problem to be affected in a torque detection accuracy.